Noah and his family had just come through an unimaginably frightening experience. Perhaps they had never even seen a storm, and certainly no one had ever seen one like this. It would have been indelibly impressed on their memories. During the Flood, the winds incessantly howled, the thunder continually pealed as the Ark pitched and rolled in the waves. Earthquakes shook the planet without stop, sending pulsating tsunamis in every direction. Underwater volcanoes and the spreading "fountains of the great deep" (Genesis 7:11) heated the water surrounding the Ark, making life on board almost unbearable. And the never ceasing rainfall so pelted the Ark's roof, it was like being under Niagara Falls.
This was not merely a category 5 hurricane of today. Creationists have begun to speculate on the nature of "hypercanes," storms dozens of times greater than present hurricanes as the primary Flood character. Surely, the world before the Flood fully "perished" (II Peter 3:6) under the Flood's onslaught.
As Noah and his family stepped off the Ark they entered a world totally unfamiliar to them. The geography had all changed. Plant and animal life had been devastated. Weather patterns were chaotic. Gone was the pre-Flood stability they were accustomed to.
Consider that the world was "broken." To the extent that we enjoy relative stability now, they had none then. It would perhaps have taken several centuries for Earth to settle down to the pseudo-equilibrium in which we now live. Remember that the jet streams must be stabilized. The ocean currents must find their "paths of the seas" (Psalm 8:8). The continents must halt their rapid horizontal movements and cease their vertical rebounding. In particular, the oceans must give up their excess heat, which drove such violent storm patterns.
It was into this unstable world Noah and his family was placed. No doubt earthquakes were common. Of necessity they lived in tents, for buildings could not be made stable. Wood was in short supply and rock structures were the least safe.
Rainfall continued its intensity, with swollen streams and violent storms. Calculations show that the ocean's heat would take at least 600 years or so to dissipate, and that during this period the "Ice Age" dominated. Job lived soon after the Flood, and his book contains more references to ice and snow than the rest of the Bible put together. Up until perhaps the time of Abraham the world was a dangerous place. Continual catastrophes dominated their lives.
No doubt they needed reassurance that there would never be another Flood like the Great Flood of Noah's day, for it must have seemed they were still in it. Thus it was out of God's grace and mercy that He instituted this beautiful reminder of His protection. And every time they saw a majestic rainbow it would remind them of the security they have in Him. And what a blessed thing it is to rest in that certain knowledge.
Cite this article: Morris, J. 2006. Why Did God Give the Rainbow Sign? Acts & Facts. 35 (1).